Tarig Ali

Development of a Seamless Topographic / Bathymetric Digital Terrain Model for Tampa Bay, Florida

This applications paper presents the methods used to create a seamless topobathy digital terrain model (DTM) at 50-foot resolution intended to support hurricane storm surge modeling in Tampa Bay, Florida. Lidar, bathymetry, and various breakline data were integrated using the Terrain Data Set structure in ArcGIS ® . The use of the Terrain Data Set structure allowed for embedding large data sets (such as lidar points) and archiving them after DTM creation while maintaining topographic analysis capabilities. The bathymetric data, natively referenced to Mean Sea Level (MSL), were converted to North American Vertical Datum of 1988 (NAVD88) using an inverse distance weighted average offset from the three nearest NOAA tidal benchmark stations; results of this conversion were within 6.1 centimeters of those produced by NOAA VDatum software in a quality control test area. This methodology can therefore be used in coastal regions of other countries.

Study of Water Quality in Dubai Creek Using DubaiSat-1 Multispectral Imagery

Dubai has witnessed enormous infrastructural developments within the recent decades resulting in rapid changes, which have detrimental effects on the environment. A major attraction in Dubai is Dubai Creek, which is a saltwater stream that divides the city into two major sub-areas known as Bur Dubai and Deira. The creek is playing a major role in commerce and tourism following a few successful dredging efforts. Due to high level of anthropogenic activities, the creek has been viewed as a source of concern. Study of the variability of water quality parameters can help in understanding the pattern of changes and assessing the sustainability of the creek. DubaiSat-1 imagery and field data for monitoring stations along the creek have been utilized to study the variability of chlorophyll-a as essential algal growth indicator. Based on this study, the implications of the urban development on the variability of the concentrations of chlorophyll-a, phosphates, and total nitrogen in the creek are evident. The analysis shows a high correlation between the spectral-based chlorophyll-a concentrations, field-based phosphates and total nitrogen concentrations; as expected. Given the study timeframe, the fluctuation pattern of the concentrations of chlorophyll-a and the limiting nutrients calls for the implementation of a mitigation plan, which will ensure the sustainability of the creek.